QtGui.QGraphicsEffect Class Reference

The QGraphicsEffect class is the base class for all graphics effects. More...

Inheritance diagram for QtGui.QGraphicsEffect:

Collaboration diagram for QtGui.QGraphicsEffect:

Public Types
enum	ChangeFlag { SourceAttached = 1, SourceBoundingRectChanged = 4, SourceDetached = 2, SourceInvalidated = 8 }
	More...
enum	PixmapPadMode { NoPad = 0, PadToEffectiveBoundingRect = 2, PadToTransparentBorder = 1 }
	More...

Public Member Functions
	QGraphicsEffect (QObject parent=null)
override void	CreateProxy ()
new QRectF	BoundingRect ()
virtual QRectF	BoundingRectFor (QRectF sourceRect)
new void	Update ()
new void	Dispose ()
Public Member Functions inherited from QtCore.QObject
	QObject (QObject parent=null)
new bool	BlockSignals (bool b)
new System.Collections.Generic.List < QObject >	Children ()
new bool	Connect (QObject sender, string signal, string member, Qt.ConnectionType type=Qt.ConnectionType.AutoConnection)
new void	DeleteLater ()
new bool	Disconnect (QObject receiver, string member=null)
new bool	Disconnect (string signal=null, QObject receiver=null, string member=null)
new void	DumpObjectInfo ()
new void	DumpObjectTree ()
new System.Collections.Generic.List < QByteArray >	DynamicPropertyNames ()
virtual bool	OnEvent (QEvent arg1)
virtual bool	EventFilter (QObject arg1, QEvent arg2)
new bool	Inherits (string classname)
new void	InstallEventFilter (QObject arg1)
new bool	IsWidgetType ()
new void	KillTimer (int id)
new object	Property (string name)
new void	RemoveEventFilter (QObject arg1)
new bool	SetProperty (string name, object value)
new void	SetUserData (uint id, QObjectUserData data)
new bool	SignalsBlocked ()
new int	StartTimer (int interval)
new QObjectUserData	UserData (uint id)
new void	Dispose ()
Public Member Functions inherited from QtCore.Qt
delegate QTextStream	FuncQTextStreamQTextStream (QTextStream qTextStream)
delegate string	FuncStringQByteArray (QByteArray qByteArray)
delegate QByteArray	FuncQByteArrayString (string @string)
delegate void	ActionQtMsgTypeString (QtMsgType qtMsgType, string @string)
delegate QObject	FuncQObject ()

Static Public Member Functions
static string	Tr (string s, string c=null)
static string	Tr (string s, string c, int n)
static string	TrUtf8 (string s, string c=null)
static string	TrUtf8 (string s, string c, int n)
Static Public Member Functions inherited from QtCore.QObject
static bool	Connect (QObject sender, QMetaMethod signal, QObject receiver, QMetaMethod method, Qt.ConnectionType type=Qt.ConnectionType.AutoConnection)
static bool	Connect (QObject sender, string signal, QObject receiver, string member, Qt.ConnectionType arg5=Qt.ConnectionType.AutoConnection)
static bool	Disconnect (QObject sender, QMetaMethod signal, QObject receiver, QMetaMethod member)
static bool	Disconnect (QObject sender, string signal, QObject receiver, string member)
static uint	RegisterUserData ()
static string	Tr (string s, string c=null)
static string	Tr (string s, string c, int n)
static string	TrUtf8 (string s, string c=null)
static string	TrUtf8 (string s, string c, int n)
Static Public Member Functions inherited from QtCore.Qt
static QDataStream	Write (QDataStream s, object p)
static QDataStream	Write (QDataStream arg1, QSizeF arg2)
static QTextStream	Write (QTextStream s, Qt.FuncQTextStreamQTextStream f)
static QDataStream	Write (QDataStream arg1, QPoint arg2)
static QDataStream	Write (QDataStream arg1, QLineF arg2)
static QDataStream	Write (QDataStream arg1, QPointF arg2)
static QDataStream	Write (QDataStream arg1, QChar arg2)
static QDataStream	Write (QDataStream arg1, QByteArray arg2)
static QDataStream	Write (QDataStream arg1, QEasingCurve arg2)
static QDataStream	Write (QDataStream arg1, QRectF arg2)
static QDataStream	Write (QDataStream arg1, QDateTime arg2)
static QDataStream	Write (QDataStream arg1, QUrl arg2)
static QDataStream	Write (QDataStream arg1, QTime arg2)
static QDataStream	Write (QDataStream arg1, QLocale arg2)
static QDataStream	Write (QDataStream arg1, QBitArray arg2)
static QDataStream	Write (QDataStream arg1, QUuid arg2)
static QDataStream	Write (QDataStream arg1, QLine arg2)
static QDataStream	Write (QDataStream arg1, QDate arg2)
static QDataStream	Write (QDataStream @out, QRegExp regExp)
static QDataStream	Write (QDataStream arg1, QRect arg2)
static QDataStream	Write (QDataStream arg1, QSize arg2)
static QDataStream	Write (QDataStream s, QVariant.Type p)
static QDataStream	Write (QDataStream arg1, string arg2)
static QDataStream	Write (QDataStream @out, System.Collections.Generic.List< string > list)
static QDataStream	Read (QDataStream arg1, QChar arg2)
static QDataStream	Read (QDataStream arg1, QLocale arg2)
static QDataStream	Read (QDataStream arg1, QRect arg2)
static QDataStream	Read (QDataStream arg1, QEasingCurve arg2)
static QDataStream	Read (QDataStream arg1, QDate arg2)
static QDataStream	Read (QDataStream arg1, QUrl arg2)
static QDataStream	Read (QDataStream arg1, QUuid arg2)
static QTextStream	Read (QTextStream s, Qt.FuncQTextStreamQTextStream f)
static QDataStream	Read (QDataStream arg1, QLineF arg2)
static QDataStream	Read (QDataStream arg1, QRectF arg2)
static QDataStream	Read (QDataStream arg1, QPointF arg2)
static QDataStream	Read (QDataStream arg1, QLine arg2)
static QDataStream	Read (QDataStream arg1, QBitArray arg2)
static QDataStream	Read (QDataStream arg1, QSize arg2)
static QDataStream	Read (QDataStream arg1, QDateTime arg2)
static QDataStream	Read (QDataStream arg1, QTime arg2)
static QDataStream	Read (QDataStream arg1, QPoint arg2)
static QDataStream	Read (QDataStream @in, QRegExp regExp)
static QDataStream	Read (QDataStream s, object p)
static QDataStream	Read (QDataStream arg1, QByteArray arg2)
static QDataStream	Read (QDataStream arg1, QSizeF arg2)
static QDataStream	Read (QDataStream arg1, string arg2)
static QDataStream	Read (QDataStream s, QVariant.Type p)
static QDataStream	Read (QDataStream @in, System.Collections.Generic.List< string > list)
static double	qAcos (double v)
static void	qAddPostRoutine (System.Action arg1)
static string	qAppName ()
static double	qAsin (double v)
static double	qAtan (double v)
static double	qAtan2 (double x, double y)
static void	qBadAlloc ()
static int	qCeil (double v)
static ushort	qChecksum (string s, uint len)
static QByteArray	qCompress (QByteArray data)
static QByteArray	qCompress (QByteArray data, int compressionLevel=-1)
static QByteArray	qCompress (Pointer< byte > data, int nbytes)
static QByteArray	qCompress (Pointer< byte > data, int nbytes, int compressionLevel=-1)
static double	qCos (double v)
static double	qExp (double v)
static double	qFabs (double v)
static double	qFastCos (double x)
static double	qFastSin (double x)
static string	qFlagLocation (string method)
static int	qFloor (double v)
static bool	qFuzzyCompare (double p1, double p2)
static bool	qFuzzyCompare (float p1, float p2)
static bool	qFuzzyIsNull (double d)
static bool	qFuzzyIsNull (float f)
static uint	qHash (QBitArray key)
static uint	qHash (QChar key)
static uint	qHash (QStringRef key)
static uint	qHash (QUrl url)
static uint	qHash (QPersistentModelIndex index)
static uint	qHash (QByteArray key)
static uint	qHash (QModelIndex index)
static uint	qHash (uint key)
static uint	qHash (sbyte key)
static uint	qHash (byte key)
static uint	qHash (short key)
static uint	qHash (NativeLong key)
static uint	qHash (ushort key)
static uint	qHash (long key)
static uint	qHash (ulong key)
static uint	qHash (int key)
static uint	qHash (string key)
static uint	qHash (NativeULong key)
static double	qInf ()
static Qt.ActionQtMsgTypeString	qInstallMsgHandler (Qt.ActionQtMsgTypeString arg1)
static int	qIntCast (float f)
static int	qIntCast (double f)
static bool	qIsFinite (double d)
static bool	qIsFinite (float f)
static bool	qIsInf (float f)
static bool	qIsInf (double d)
static bool	qIsNaN (float f)
static bool	qIsNaN (double d)
static bool	qIsNull (float f)
static bool	qIsNull (double d)
static double	qLn (double v)
static double	qPow (double x, double y)
static double	qQNaN ()
static void	qRegisterStaticPluginInstanceFunction (Qt.FuncQObject function)
static void	qRemovePostRoutine (System.Action arg1)
static int	qRound (double d)
static long	qRound64 (double d)
static double	qSNaN ()
static bool	qSharedBuild ()
static double	qSin (double v)
static double	qSqrt (double v)
static bool	qStringComparisonHelper (QStringRef s1, string s2)
static double	qTan (double v)
static QByteArray	qUncompress (QByteArray data)
static QByteArray	qUncompress (Pointer< byte > data, int nbytes)
static string	qVersion ()
static void	Qbswap_helper (Pointer< byte > src, Pointer< byte > dest, int size)
static QByteArray	Qgetenv (string varName)
static bool	Qputenv (string varName, QByteArray value)
static int	Qrand ()
static void	Qsrand (uint seed)
static int	Qstrcmp (QByteArray str1, QByteArray str2)
static int	Qstrcmp (QByteArray str1, string str2)
static int	Qstrcmp (string str1, QByteArray str2)
static int	Qstrcmp (string str1, string str2)
static Pointer< sbyte >	Qstrcpy (Pointer< sbyte > dst, string src)
static Pointer< sbyte >	Qstrdup (string arg1)
static int	Qstricmp (string arg1, string arg2)
static uint	Qstrlen (string str)
static int	Qstrncmp (string str1, string str2, uint len)
static Pointer< sbyte >	Qstrncpy (Pointer< sbyte > dst, string src, uint len)
static int	Qstrnicmp (string arg1, string arg2, uint len)
static uint	Qstrnlen (string str, uint maxlen)
static string	QtTrId (string id, int n=-1)

Protected Member Functions
	QGraphicsEffect (System.Type dummy)
abstract void	Draw (QPainter painter)
new void	DrawSource (QPainter painter)
new void	OnEnabledChanged (bool enabled)
new QRectF	SourceBoundingRect (Qt.CoordinateSystem system=Qt.CoordinateSystem.LogicalCoordinates)
virtual void	SourceChanged (QGraphicsEffect.ChangeFlag flags)
new bool	SourceIsPixmap ()
new QPixmap	SourcePixmap (Qt.CoordinateSystem system=Qt.CoordinateSystem.LogicalCoordinates, QPoint offset=null, QGraphicsEffect.PixmapPadMode mode=QGraphicsEffect.PixmapPadMode.PadToEffectiveBoundingRect)
new void	UpdateBoundingRect ()
Protected Member Functions inherited from QtCore.QObject
	QObject (System.Type dummy)
virtual void	OnChildEvent (QChildEvent arg1)
virtual void	ConnectNotify (string signal)
virtual void	OnCustomEvent (QEvent arg1)
new void	OnDestroyed (QObject arg1=null)
virtual void	DisconnectNotify (string signal)
new int	Receivers (string signal)
new QObject	Sender ()
new int	SenderSignalIndex ()
virtual void	OnTimerEvent (QTimerEvent arg1)

Properties
Slot< System.Boolean >	EnabledChanged
new bool	Enabled [get, set]
static new QMetaObject	StaticMetaObject [get]
new IQGraphicsEffectSignals	Emit [get]
Properties inherited from QtCore.QObject
virtual EventHandler < QEventArgs< QChildEvent > >	ChildEvent
virtual EventHandler < QEventArgs< QEvent > >	CustomEvent
virtual EventHandler < QEventArgs< QEvent > >	Event
virtual EventHandler < QEventArgs< QTimerEvent > >	TimerEvent
Slot< QObject >	DestroyedQObject
Slot	Destroyed
new QObject	Parent [get, set]
virtual System.IntPtr	SmokeObject [get, set]
new string	ObjectName [get, set]
static new QMetaObject	StaticMetaObject [get]
static new QMetaObject	StaticQtMetaObject [get]
new IQObjectSignals	Emit [get]

Additional Inherited Members
Protected Attributes inherited from QtCore.QObject
object	Q_EMIT = null
SmokeInvocation	interceptor
readonly List< QEventHandler >	eventFilters = new List<QEventHandler>()

Detailed Description

The QGraphicsEffect class is the base class for all graphics effects.

Effects alter the appearance of elements by hooking into the rendering pipeline and operating between the source (e.g., a QGraphicsPixmapItem) and the destination device (e.g., QGraphicsView's viewport). Effects can be disabled by calling setEnabled(false). If effects are disabled, the source is rendered directly.

To add a visual effect to a QGraphicsItem, for example, you can use one of the standard effects, or alternately, create your own effect by creating a subclass of QGraphicsEffect. The effect can then be installed on the item using QGraphicsItem::setGraphicsEffect().

Qt provides the following standard effects:

QGraphicsBlurEffect - blurs the item by a given radius

QGraphicsDropShadowEffect - renders a dropshadow behind the item

QGraphicsColorizeEffect - renders the item in shades of any given color

QGraphicsOpacityEffect - renders the item with an opacity

For more information on how to use each effect, refer to the specific effect's documentation.

To create your own custom effect, create a subclass of QGraphicsEffect (or any other existing effects) and reimplement the virtual function draw(). This function is called whenever the effect needs to redraw. The draw() function takes the painter with which to draw as an argument. For more information, refer to the documenation for draw(). In the draw() function you can call sourcePixmap() to get a pixmap of the graphics effect source which you can then process.

If your effect changes, use update() to request for a redraw. If your custom effect changes the bounding rectangle of the source, e.g., a radial glow effect may need to apply an extra margin, you can reimplement the virtual boundingRectFor() function, and call updateBoundingRect() to notify the framework whenever this rectangle changes. The virtual sourceChanged() function is called to notify the effects that the source has changed in some way - e.g., if the source is a QGraphicsRectItem and its rectangle parameters have changed.

See also QGraphicsItem::setGraphicsEffect() and QWidget::setGraphicsEffect().

Member Enumeration Documentation

enum QtGui.QGraphicsEffect.ChangeFlag

This enum describes what has changed in QGraphicsEffectSource.

Enumerator:

SourceAttached	The effect is installed on a source.
SourceBoundingRectChanged	The bounding rect of the source has changed.
SourceDetached	The effect is uninstalled on a source.
SourceInvalidated	The visual appearance of the source has changed.

enum QtGui.QGraphicsEffect.PixmapPadMode

This enum describes how the pixmap returned from sourcePixmap should be padded.

Enumerator:

NoPad	The pixmap should not receive any additional padding.
PadToEffectiveBoundingRect	The pixmap should be padded to match the effective bounding rectangle of the effect.
PadToTransparentBorder	The pixmap should be padded to ensure it has a completely transparent border.

Constructor & Destructor Documentation

QtGui.QGraphicsEffect.QGraphicsEffect ( System.Type  dummy )

protected

QtGui.QGraphicsEffect.QGraphicsEffect

(

QObject

parent = null

)

Constructs a new QGraphicsEffect instance having the specified parent.

Member Function Documentation

new QRectF QtGui.QGraphicsEffect.BoundingRect

(

)

Returns the effective bounding rectangle for this effect, i.e., the bounding rectangle of the source in device coordinates, adjusted by any margins applied by the effect itself.

See also boundingRectFor() and updateBoundingRect().

virtual QRectF QtGui.QGraphicsEffect.BoundingRectFor ( QRectF  sourceRect )

virtual

Returns the effective bounding rectangle for this effect, given the provided rect in the device coordinates. When writing you own custom effect, you must call updateBoundingRect() whenever any parameters are changed that may cause this this function to return a different value.

See also sourceBoundingRect().

Reimplemented in QtGui.QGraphicsDropShadowEffect, and QtGui.QGraphicsBlurEffect.

override void QtGui.QGraphicsEffect.CreateProxy ( )

virtual

Reimplemented from QtCore.QObject.

Reimplemented in QtGui.QGraphicsOpacityEffect.

new void QtGui.QGraphicsEffect.Dispose

(

)

abstract void QtGui.QGraphicsEffect.Draw ( QPainter  painter )

protectedpure virtual

This pure virtual function draws the effect and is called whenever the source needs to be drawn.

Reimplement this function in a QGraphicsEffect subclass to provide the effect's drawing implementation, using painter.

For example:

MyGraphicsEffect::draw(QPainter *painter)

{

...

QPoint offset;

if (sourceIsPixmap()) {

// No point in drawing in device coordinates (pixmap will be scaled anyways).

const QPixmap pixmap = sourcePixmap(Qt::LogicalCoordinates, &offset);

...

painter->drawPixmap(offset, pixmap);

} else {

// Draw pixmap in device coordinates to avoid pixmap scaling;

const QPixmap pixmap = sourcePixmap(Qt::DeviceCoordinates, &offset);

painter->setWorldTransform(QTransform());

...

painter->drawPixmap(offset, pixmap);

}

...

}

This function should not be called explicitly by the user, since it is meant for reimplementation purposes only.

Implemented in QtGui.QGraphicsOpacityEffect, QtGui.QGraphicsDropShadowEffect, QtGui.QGraphicsColorizeEffect, and QtGui.QGraphicsBlurEffect.

new void QtGui.QGraphicsEffect.DrawSource ( QPainter  painter )

protected

Draws the source directly using the given painter.

This function should only be called from QGraphicsEffect::draw().

For example:

MyGraphicsOpacityEffect::draw(QPainter *painter)

{

// Fully opaque; draw directly without going through a pixmap.

if (qFuzzyCompare(m_opacity, 1)) {

drawSource(painter);

return;

}

...

}

See also QGraphicsEffect::draw().

new void QtGui.QGraphicsEffect.OnEnabledChanged ( bool  enabled )

protected

This signal is emitted whenever the effect is enabled or disabled. The enabled parameter holds the effects's new enabled state.

See also isEnabled().

new QRectF QtGui.QGraphicsEffect.SourceBoundingRect ( Qt.CoordinateSystem  system = Qt.CoordinateSystem.LogicalCoordinates )

protected

Returns the bounding rectangle of the source mapped to the given system.

Calling this function with Qt::DeviceCoordinates outside of QGraphicsEffect::draw() will give undefined results, as there is no device context available.

See also draw().

virtual void QtGui.QGraphicsEffect.SourceChanged ( QGraphicsEffect.ChangeFlag  flags )

protectedvirtual

This virtual function is called by QGraphicsEffect to notify the effect that the source has changed. If the effect applies any cache, then this cache must be purged in order to reflect the new appearance of the source.

The flags describes what has changed.

new bool QtGui.QGraphicsEffect.SourceIsPixmap ( )

protected

Returns true if the source effectively is a pixmap, e.g., a QGraphicsPixmapItem.

This function is useful for optimization purposes. For instance, there's no point in drawing the source in device coordinates to avoid pixmap scaling if this function returns true - the source pixmap will be scaled anyways.

new QPixmap QtGui.QGraphicsEffect.SourcePixmap ( Qt.CoordinateSystem  system = Qt.CoordinateSystem.LogicalCoordinates, QPoint  offset = null, QGraphicsEffect.PixmapPadMode  mode = QGraphicsEffect.PixmapPadMode.PadToEffectiveBoundingRect  )

protected

Returns a pixmap with the source painted into it.

The system specifies which coordinate system to be used for the source. The optional offset parameter returns the offset where the pixmap should be painted at using the current painter. For control on how the pixmap is padded use the mode parameter.

The returned pixmap is clipped to the current painter's device rectangle when system is Qt::DeviceCoordinates.

Calling this function with Qt::DeviceCoordinates outside of QGraphicsEffect::draw() will give undefined results, as there is no device context available.

See also draw() and boundingRect().

static string QtGui.QGraphicsEffect.Tr ( string  s, string  c = null  )

static

static string QtGui.QGraphicsEffect.Tr ( string  s, string  c, int  n  )

static

static string QtGui.QGraphicsEffect.TrUtf8 ( string  s, string  c = null  )

static

static string QtGui.QGraphicsEffect.TrUtf8 ( string  s, string  c, int  n  )

static

new void QtGui.QGraphicsEffect.Update

(

)

Schedules a redraw of the effect. Call this function whenever the effect needs to be redrawn. This function does not trigger a redraw of the source.

See also updateBoundingRect().

new void QtGui.QGraphicsEffect.UpdateBoundingRect ( )

protected

This function notifies the effect framework when the effect's bounding rectangle has changed. As a custom effect author, you must call this function whenever you change any parameters that will cause the virtual boundingRectFor() function to return a different value.

This function will call update() if this is necessary.

See also boundingRectFor(), boundingRect(), and sourceBoundingRect().

Property Documentation

new IQGraphicsEffectSignals QtGui.QGraphicsEffect.Emit

getprotected

new bool QtGui.QGraphicsEffect.Enabled

getset

This property holds whether the effect is enabled or not.

If an effect is disabled, the source will be rendered with as normal, with no interference from the effect. If the effect is enabled, the source will be rendered with the effect applied.

This property is enabled by default.

Using this property, you can disable certain effects on slow platforms, in order to ensure that the user interface is responsive.

Slot<System.Boolean> QtGui.QGraphicsEffect.EnabledChanged

addremove

This signal is emitted whenever the effect is enabled or disabled. The enabled parameter holds the effects's new enabled state.

See also isEnabled().

new QMetaObject QtGui.QGraphicsEffect.StaticMetaObject

staticget